Modular optical fiber cassette

ABSTRACT

The present disclosure includes apparatus and methods for a modular optical fiber cassette. One embodiment includes a base housing configured to receive additional nested components and an adapter plate resiliently connected to the housing and comprising a plurality of optical fiber connectors. The adapter plate is releasable from the housing and providing access to both sides of the adapter plate. The cassette further includes a radius limiter nested with and resiliently connected to the base housing, a first expansion housing having an exterior contour substantially aligned with the base housing and configured to resiliently interlock with the base housing, and a cover resiliently connected to the expansion housing.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part (OP) of U.S. patentapplication Ser. No. 12/552,140, filed on Sep. 1, 2009, and entitled“Modular Optical Fiber Cassette” which is a continuation-in-part (CIP)of U.S. patent application Ser. No. 12/286,554, filed on Sep. 30, 2008,and entitled “Modular Optical Fiber Cassettes and Fiber ManagementMethods,” which claims priority to U.S. Provisional Application No.60/997,170, filed on Oct. 1, 2007, the disclosures of which areincorporated in their entirety herein by reference.

BACKGROUND

An optical fiber (e.g., glass, plastic) carries light along its length.Light is kept in the core of the optical fiber by internal reflection.The optical fiber acts as a waveguide. Optical fiber can be used as acommunication medium for telecommunication and networking applicationsbecause it is flexible and can be bundled into cables. Although referredto as “optical fiber,” optical fiber is not restricted to communicatinglight in the visible spectrum, and may transmit light signals of higher,or lower, wavelengths.

Optical fiber is especially advantageous for communications becauselight propagates through the fiber with less attenuation than forelectrical signals using metal wires. This facilitates long distancecommunications using with few repeaters. And unlike electricalcommunication modes, light signals are immune to electromagneticinterference, thereby eliminating cross-talk between signals and theeffects of environmental noise. Non-armored optical fiber cables do notconduct electricity, which makes optical fiber a good solution forprotecting communications equipment located in electrically-exposedenvironments, including communication structures prone to lightningstrikes.

Optical fiber permits transmission at higher bandwidths (e.g., datarates) than other forms of communications. Per-channel light signalspropagating in the fiber can be modulated at rates in the range ofgigabits per second. An individual optical fiber can carry manyindependent channels, each using a different wavelength of light andwavelength-division multiplexing (WDM). Optical fiber saves space incable ducts because a single optical fiber can carry much more data thana single electrical cable.

A fiber optic cable is usually made up of many individual opticalfibers. For example, according to one commercially availableconfiguration, twelve (12) 250 micron optical fibers may be groupedtogether in a buffer tube. A fiber optic cable may contain 6 buffertubes (i.e., for a total of 72 optical fibers) and one or more strengthmembers (e.g., metallic member), with the buffer tubes and strengthmember being surrounded by a jacket providing physical and environmentalprotection. Other commercially available fiber optic cableconfigurations may include 144 optical fibers (e.g., 12 buffer tubes of12 optical fibers each), or 288 optical fibers (e.g., 12 buffer tubes of12 optical fibers each), among others.

Individual optical fibers (e.g., glass, plastic) can be fragile, andrequire measures to prevent fracturing, or breakage. Optical fiber canbe subject to physical routes limited to a minimum bend radius, at thecable level and/or at an individual fiber level, to prevent fracturing,breakage, or signal distortions/losses. In addition, optical fibers maybe damaged if they are subjected to excessive tension or physicalimpact. Due to the risk of damage, it is preferable to avoid handlingindividual fibers any more than is necessary.

Optical fibers are increasingly being used to provide signaltransmission between various service providers (e.g., telephone systems,video systems, computer network, etc.) and individual users (e.g.,homes, businesses). Fibers which support many propagation paths ortransverse modes are called multi-mode fibers (MMF), while those whichcan only support a single mode are called single-mode fibers (SMF). MMFgenerally have a larger core diameter, and is used for short-distancecommunication links, and SMF is used for longer distance communicationlinks. Working with optical fiber (e.g., splicing, splitting, patching)involves close tolerances, and is best accomplished in controlledenvironments where physical alignments, temperature, and cleanliness arebetter managed to facilitate precision work results.

Optical fiber connection apparatuses, such as outside plant distributioncabinets, distribution frames, patch panels, splice terminations areused wherever the interconnection or cross-connection of multipleoptical fibers is required. For example, optical fiber cable comprisingnumerous individual fibers may enter a distribution cabinet, fiberframe, or patch panel for connection to the individual optical fibersthat split off to provide service to homes or businesses. Often, it isdesirable that such optical fiber management, and/or optical fiberconnection apparatus, allow for the interconnection of a large number ofindividual fibers in as small a space as possible (e.g., high densityconnections).

It is further desirable to make the work of technicians installing andservicing the optical fiber connection apparatuses and associatedoptical fibers as simple as possible. Previous patch panel approachesmimicked electrical termination cabinets. Traditional central officefiber management uses a fixed bulkhead design and costly radius andphysical fiber protection inside an overall housing. While theseapparatus provide some protection to the connectors and fibers, thefibers may then typically be routed only through the top and bottom ofthe unit or only through slots in the side of the unit. Density istherefore sacrificed to gain protection of the connectors and fibers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a modular optic fiber cassettein accordance with one or more embodiments of the present disclosure.

FIG. 2 is a top front perspective view of an assembled modular opticfiber cassette in accordance with one or more embodiments of the presentdisclosure.

FIG. 3 is a top rear perspective view of the assembled modular opticfiber cassette of FIG. 2 in accordance with one or more embodiments ofthe present disclosure.

FIG. 4 is a top rear perspective view of a modular optic fiber cassettehaving a second configuration in accordance with one or more embodimentsof the present disclosure.

FIG. 5 is a top rear perspective view of a modular optic fiber cassettehaving a third configuration in accordance with one or more embodimentsof the present disclosure.

FIG. 6 is a top front perspective view of a modular optic fiber cassettehousing in accordance with one or more embodiments of the presentdisclosure.

FIG. 7 is a bottom front perspective view of the modular optic fibercassette housing of FIG. 6 in accordance with one or more embodiments ofthe present disclosure.

FIG. 8 is a top rear perspective view of the modular optic fibercassette housing of FIG. 6 in accordance with one or more embodiments ofthe present disclosure.

FIG. 9 is a top perspective view of a radius limiter in accordance withone or more embodiments of the present disclosure.

FIG. 10 is a bottom perspective view of the radius limiter of FIG. 9 inaccordance with one or more embodiments of the present disclosure.

FIG. 11 is a top front perspective view of a splice tray in accordancewith one or more embodiments of the present disclosure.

FIG. 12 is a bottom front perspective view of the splice tray of FIG. 11in accordance with one or more embodiments of the present disclosure.

FIG. 13 is a detail view of a portion of the splice tray of FIG. 11showing in particular a fiber nest and splice channels in accordancewith one or more embodiments of the present disclosure.

FIG. 14 is a top front perspective view of a modular optic fibercassette housing cover in accordance with one or more embodiments of thepresent disclosure.

FIG. 15 is a bottom front perspective view of the modular optic fibercassette housing cover of FIG. 14 in accordance with one or moreembodiments of the present disclosure.

FIG. 16 is a front perspective view of a modular optic fiber cassettehousing having a radius limiter nested in the optic fiber cassettehousing with plural fibers (partial view) connected to an adapter plateand looped around the radius limiter in accordance with one or moreembodiments of the present disclosure.

FIG. 17 is a front perspective view of a modular optic fiber cassettehousing having an adapter plate extended away from the optic fibercassette housing in accordance with one or more embodiments of thepresent disclosure.

FIG. 18 is a front perspective view of a modular optic fiber cassettehousing having a pre-loaded splice tray nested in the optic fibercassette housing in accordance with one or more embodiments of thepresent disclosure.

FIG. 19 is a front perspective view of a modular optic fiber cassettehousing having a splice tray nested in the optic fiber cassette housingin accordance with one or more embodiments of the present disclosure.

FIG. 20 is a front perspective view of a modular optic fiber cassettehousing having a modular optical component nested in the optic fibercassette housing in accordance with one or more embodiments of thepresent disclosure.

FIG. 21 is an exploded perspective view of a modular optic fibercassette including a housing base and expansion housing in accordancewith one or more embodiments of the present disclosure.

FIG. 22 is a top front perspective view of a modular optic fibercassette including a housing base and expansion housing in accordancewith one or more embodiments of the present disclosure.

FIG. 23 is a top rear perspective view of a modular optic fiber cassetteof including a housing base and housing extender in accordance with oneor more embodiments of the present disclosure.

FIG. 24 is a top front perspective view of a modular optic fibercassette expansion housing in accordance with one or more embodiments ofthe present disclosure.

FIG. 25 is a bottom front perspective view of a modular optic fibercassette expansion housing in accordance with one or more embodiments ofthe present disclosure.

FIG. 26 is a top rear perspective view of a modular optic fiber cassetteexpansion housing in accordance with one or more embodiments of thepresent disclosure.

FIG. 27 is a optic fiber communication system in accordance with one ormore embodiments of the present disclosure.

FIG. 28A illustrates an optical fiber management housing in an unfoldedconfiguration in accordance with one or more embodiments of the presentdisclosure.

FIG. 28B illustrates an optical fiber management housing in an unfoldedconfiguration in accordance with one or more embodiments of the presentdisclosure.

FIG. 28C illustrates an optical fiber management housing in a foldedconfiguration in accordance with one or more embodiments of the presentdisclosure.

FIG. 28D illustrates an optical fiber management housing in a foldedconfiguration in accordance with one or more embodiments of the presentdisclosure.

FIG. 28E illustrates a rear view of the optical fiber management housingembodiments illustrated in FIGS. 28C and 28D.

DETAILED DESCRIPTION

The present disclosure includes apparatus and methods for a modularoptical fiber cassette. One embodiment includes a base housingconfigured to receive additional nested components and an adapter plateresiliently connected to the housing and comprising a plurality ofoptical fiber connectors. The adapter plate is releasable from thehousing and providing access to both sides of the adapter plate. Thecassette further includes a radius limiter nested with and resilientlyconnected to the base housing, a first expansion housing having anexterior contour substantially aligned with the base housing andconfigured to resiliently interlock with the base housing, and a coverresiliently connected to the expansion housing.

The present disclosure provides modular cassettes and methods for fibermanagement applications that satisfy all the basic principals of fibermanagement with such cassettes. Cassettes in accordance with the presentdisclosure comprise plural functional components that nest into a mainhousing portion to support various application and fiber types. Inaccordance with the present disclosure, such components can be added orremoved depending on the application and configuration needs of the useenvironment. Advantageously, cassettes in accordance with the presentdisclosure incorporate resilient connections and nested internalcomponents for easy assembly and disassembly with minimal fastenersand/or tools.

Furthermore, the present disclosure provides cable management cassettesand management techniques that include one or more of the followingcapabilities: patch only configuration by configuring a cassette to notinclude a splice tray thereby saving installed costs; patch and spliceconfiguration to reduce costs without giving up convenience and/or thequality of splicing that traditional patch-only environments providewhen multi-buffer tubes or subunit cable is being used; reducing risk byeliminating as much interaction with fiber jumpers and tail as possibleby having a removable adapter plate allowing access to both sides ofconnectors for installation, cleaning and maintenance, particularly whenin-service; and permitting modularity in the quantity of fiber beingmanaged to balance present capital costs with future expandability.

In the following detailed description of the present disclosure,reference is made to the accompanying drawings that form a part hereof,and in which is shown by way of illustration how one or more embodimentsof the disclosure may be practiced. These embodiments arc described insufficient detail to enable those of ordinary skill in the art topractice the embodiments of this disclosure, and it is to be understoodthat other embodiments may be utilized and that process, electrical,and/or structural changes may be made without departing from the scopeof the present disclosure. The last three digits of reference numberscorrespond to an item, with preceding digits corresponding to thedrawing number. For example, one cassette embodiment of the presentdisclosure is indicated by the reference number 1010 with respect toFIG. 1, and a similar cassette embodiment is indicated by the referencenumber 2010 with respect to FIG. 2.

FIG. 1 is an exploded perspective view of a modular optic fiber cassettein accordance with one or more embodiments of the present disclosure.Modular optical fiber cassette 1010 (hereinafter “cassette”), as shown,comprises a base housing 1012, adapter plate 1014, radius limiter 1016,splice tray 1018, splice tray cover 1020, and housing cover 1022.

While cassette 1010 is shown in FIG. 1 as including all of theabove-mentioned components, embodiments of the present disclosure arenot so limited, and a particular cassette 1010 may be assembled toinclude additional components not shown in FIG. 1, or less than all thecomponents illustrated in FIG. 1, depending on a particular applicationfor cassette 1010.

Cassettes in accordance with the present disclosure can be used for bothinside and outside plant environments. Cassettes in accordance with thepresent disclosure are made from materials suitable for harsh outsideplant environments. Such cassettes are scalable to provide a range ofport density and application needs.

One or more fiber optic cables comprising plural individual fibers maybe provided to cassette 1010, for example, through openings 1021, 1024,1026, 1032, and 1034, among others. Such fiber optic cable may be brokenout to (distributed as) individual fibers within cassette 1010. Minimumbend radius specifications for such fibers can be maintained by cassette1010 such as by using radius limiter 1016, for example. Cassette 1010can also facilitate splitting or splicing individual fibers of a fiberoptic cable to adapter plate 1014 which provides plural connectors 1015(e.g., twelve, as illustrated) for connecting to individual fibers(e.g., of the fiber optic cable provided to cassette 1010).

Advantageously, cassette 1010 is modular and individual components ofcassette 1010 functionally nest with each other for easy reliableassembly, disassembly, and/or maintenance. Moreover, cassette 1010utilizes resilient connections, such as snap-fit connections, forexample, which provides the ability to assemble and disassemble cassette1010 with minimal or no tools and/or fasteners.

Advantageously, housing 1012, radius limiter 1016, splice tray 1018,splice tray cover 1020, and housing cover 1022 of cassette 1010 comprisesubstantially clear plastic or the like allowing for a quick and easyfirst-step troubleshooting of unacceptable light leakage. By clear it ismeant that the material used for cassette 1010 is at least partiallytransmissive of a desired wavelength or range of wavelengths usable foridentifying problems with fibers within cassette 1010 such as breaks,fractures, cracks, or other unacceptable conditions. In a variousembodiments, cassette 1010 comprises plastic that is at least partiallytransmissive of visible light so problems with fibers inside cassette1010 can he visibly identified without opening cassette 1010. Forexample, light leakage indicative of connection problems is observablethrough plastic that is at least partially transmissive of light.Furthermore, when using colored buffer tubes following EIA/TIA colorcode (e.g., for 12 fiber bundles), a cassette that is at least partiallytransmissive of visible light (e.g., clear) permits easy identificationof a particular fiber (e.g., identified by its particular color coding),or fiber number, if a break or other damage thereto has occurred.

In one or more embodiments, splice tray 1018 is configured to hesubstantially opaque while base housing 1012 and housing cover 1022 areclear. By substantially opaque it is meant that the material is nottransmissive of a desired wavelength or range of wavelengths usable foridentifying problems with fibers within cassette 1010. Splice tray 1018is made of material that makes it easier to see an unacceptablecondition of an optical fiber within cassette 1010 such as a break orcrack or the like by providing contrast between a light signal in suchoptical fiber and splice tray 1018. As an example, colored plastic canbe used such as black, blue, brown, or white, to make it easier to seean unacceptable optical fiber condition within cassette 1010 when beingtested for such conditions. In this way, because base housing 1012 andhousing cover 1022 are clear, troubleshooting can be performed withouthaving to open the cassette to reveal the internal contents. Componentsof cassette 1010 may also be color coded in any desired way to aid inquickly identifying such components. For example, in one embodiment,radius limiter 1016 is made from blue plastic.

Cassette 1010 also comprises ruggedized plastic components suitable forharsh outside plant temperature and environmental conditions such as foruse in outside plant cabinets for FTTx applications. Fiber to the home,business, premise, etc. is often referred to as FTTH (fiber to thehome), FTTP (fiber to the premise) where FTTx is a generic term for allend-points of an all fiber network to an end user. Advantageously,cassette 1010, because of its modularity, can be used from centraloffice to outside plant thereby reducing the learning curve and serviceturn-up time due to familiarity of cassette 1010 throughout the network.

Adapter plate 1014 comprises internal connectors 1017, which function toprovide a connection between adapter plate 1014 and fibers withincassette 1010 and external connectors 1015, which function to connectfibers within cassette 1010 and other desired components. Adapter plate1014 may comprise any desired number of connections. Adapter plate 1014also comprises fastener 1040 used to attach adapter plate 101.4 toopening 1042 in flange 1044 of base housing 1012 and fastener 1046 usedto attach adapter plate 1014 to opening 1048 in flange 1050 of basehousing 1012. Fasteners 1040 and 1046 can use resilient connections toattach adapter plate 1014 to base housing 1012. A resilient connectioncan comprise a flexible elastic portion that can flex or deflect toengage with a corresponding portion, which may be a flexible portion aswell. Resilient connections can be engaged and disengaged, such as forassembly and disassembly of components, with minimal or no tools and/orfasteners. Conventional fasteners may be used, however, such as screwsand bolts and the like.

FIG. 2 is a top front perspective view, and FIG. 3 is a top rearperspective view, of an assembled modular optic fiber cassette inaccordance with one or more embodiments of the present disclosure. Acassette (e.g., 2010 in FIG. 2 and/or 3010 in FIG. 3) can include anumber of anchoring locations. For example, a right side anchor tab 2047shown in FIG. 2 and/or a left side anchor tab 3049 shown in FIG. 3 canbe used to mount or secure the cassette 2010 to another structure, suchas a rack for rack mounting, wall, cabinet, frame, pedestal, etc. Rightside anchor point 2056 shown in FIG. 2, left side anchor point 3052 andrear anchor point 3054 shown in FIG. 3. Anchor points 2056, 3052 and3054 can be used to gang or group plural cassettes together into oneblock, for easier installation and shipping, and therefore can also bereferred to as “ganging loops.”

The respective anchor points can be a loop extending from the basehousing (e.g., 2012, 3012), as illustrated in FIGS. 2 and 3. Accordingto one or more embodiments of the present disclosure, the anchor pointsare configured as loops of sufficient size to allow a cable tic (e.g.,zip tie), for example, to be passed through the loop of adjacentcassettes, and thereby fastened together. The anchor points are arrangedalong the base housing (e.g., 2012) sidewall portion (e.g., 6058indicated in FIG. 6) so as not to extend the across the entire verticaldimension thereof. In one or more embodiments, the anchor points arecentrally located in the vertical dimension, with sufficient spaceabove, below, or both above and below the anchor point to accommodatethe closure portion of a cable tie in said space such that the closureportion of the cable tie is substantially vertically aligned with theanchor points, rather than extending horizontally beyond the anchorpoints.

As the cassettes are modular handling units of 12 fibers, the quantityof cassettes may be selected to accommodate a presently used fibercount, and subsequently modified to accommodate a different future fibercount. For example, a 288-port cabinet may be initially loaded with 144ports (e.g., less than the full capacity of the cabinet) using 12cassettes, each cassette terminating 12 fibers. If in the future thereis a need for additional fiber capacity in the cabinet, a number ofpre-terminated cassettes (e.g., 12 cassettes, each terminating 12fibers, for a total of an additional 144 fibers) can be added to thecabinet. The 12 new cassettes can be ganged (e.g., fastened) togetherinto a solid block for easier installation and handling.

Port capacity can be added in patch only, or patch and splice,configurations. Cassettes having different configurations can be mixedand matched in a particular installation as desired or needed by a user.For example, a cabinet can be used to initially deploy one or morecassettes having a patch only configuration. Subsequently, due topreviously unforeseen subscriber demand, additional cassettes having apatch and splice configuration can be added to the cabinet toaccommodate the unforeseen demand or future growth. The capability toadd cassettes of different configurations as needed over time, or evenre-configuring particular cassettes of a given installation, facilitatesa modular fiber management solution that avoids capital investment untilneeded, thereby lowering costs.

FIG. 3 is a top rear perspective view of the assembled modular opticfiber cassette of FIG. 2 in accordance with one or more embodiments ofthe present disclosure. FIG. 3 illustrates connectors 3031 and 3033being operatively attached to cassette 3010 (e.g., at opening 1021, asshown in FIG. 1). In addition, one or more fiber optic cables (notshown) having plural fibers to be managed by cassette 3010 anddistributed by adapter plate 3014 can be provided to cassette 3010 usingopenings 3024 and 3026 as shown in FIG. 3. Openings 3024 and 3026 areprovided at opposite sides of cassette 3010, as illustrated, whichprovides easy access to one or both sides of cassette 3010 depending onhow the cassette is used. Openings 3024 and 3026 can be used for entryand/or exit of fiber optic cables.

One or more fiber optic cables (not shown) having plural fibers to bemanaged by cassette 3010 and distributed by adapter plate 3014 can alsobe provided to cassette 3010 using openings, 3032 and 3034, as shown inFIG. 3. Openings, 3032 and 3034, are designed to receive connectors thatcan be used for plug-n-play applications where a fiber optic cable to bedistributed using cassette 3010 comprise a suitable connector at an endof the fiber optic cable. Connectors 3032 and 3034 may compriseconnectors such as those for multi-fiber optical ribbon connectors(e.g., MPT, MPO) where a 4, 8, or 12, etc. fiber ribbon is terminatedinto a single connector. The application of MTP/MPO provides plug-n-playfunctionality. A fiber assembly of a 12-fiber MTP connector broken outto individual 12-fiber circuits terminated to adapter plate 3014 ofcassette 3010 allows a user to bring a pre-terminated MTP/MPO assemblyto cassette 3010 and simply plug into the MTP/MPO adapter integratedwith housing 3012.

FIG. 4 is a top rear perspective view of a modular optic fiber cassettehaving a second configuration in accordance with one or more embodimentsof the present disclosure. FIG. 4 illustrates connectors 4036 and 4038being operatively attached to cassette 4010 (e.g., at respectiveopenings 3032 and 3034, as shown in FIG. 3). Opening 4024 (similar toopening 1024 in FIG. 1) and opening 4021 (similar to opening 1021 inFIG. 1) are also shown in FIG. 4 for reference.

FIG. 5 is a top rear perspective view of a modular optic fiber cassettehaving a third configuration in accordance with one or more embodimentsof the present disclosure. FIG. 5 illustrates strain relief tubes 5028and 5030 being operatively attached to cassette 5010 (e.g., atrespective openings 3024 and 3026 in FIG. 3). However, embodiments ofthe present disclosure are not limited to the particular strain relieftubes 5028 and 5030 shown in FIG. 5, and other grommets, clamps, and/orstrain relief tube configurations compatible with a particular openinggeometry of the cassette entry/exit points can be used to provideappropriate security to a fiber optic cable being terminated to cassette5010 using the rear openings (e.g., 3024 and 3026 shown in FIG. 3).Anchor point 5054 is indicated on the rear of cassette 5010, similar toanchor point 3054 on cassette 3010 in FIG. 3. Adapter plate 5014,comprising multiple external connectors 1015, similar to adapter plate2014 and connectors 2015 in FIG. 2, are also shown in FIG. 5.

FIG. 6 is a top front perspective view of a modular optic fiber cassettehousing in accordance with one or more embodiments of the presentdisclosure. FIG. 6 illustrates a base housing 6012 in greater detailthan FIG. 1. Base housing 6012 comprises a floor portion 6057, one ormore sidewall portions 6058 substantially perpendicular to the internalfloor portion 6057, and a front opening 6060 for receiving an adapterplate (e.g., 1014 shown in FIG. 1).

Base housing 6012 includes a number of openings (e.g., 6021, 6024, amongothers) through which one or more fiber optic cables may enter basehousing 6012, for example, through different style connectors as shownin FIGS. 3-5, among others. FIG. 6 also illustrates a top view of anchorpoints 6052 and 6056, showing the vertical offset away from the top edgeof the sidewall portion 6058 of the base housing 6012.

Floor portion 6057 can include mounting regions 6062, 6064, 6068, and6066, which may be raised regions or standoffs as viewed from the insideof housing 6012. Mounting regions 6062, 6064, 6066, and 6068 function toprovide internal attachment points for optical components, if used,which are shown in FIG. 20 and discussed later. Floor portion 6057 canalso include bosses 6098 and 6100, for mating with a radius limiter(e.g., 1016 in FIG. 1), and one or more stand-offs 6061, upon whichnested components (e.g., splice tray 1018 shown in FIG. 1) can besupported. The one or more stand-offs 6061 also keep slack stored fiberconfined to a particular route path within the cassette. FIG. 18 furtherillustrates this feature.

Base housing 6012 includes a number of engaging arms 6088, 6090, and6092. Engaging arms 6088, 6090, and 6092 comprise hook portions at theend of each arm that engage with notches (e.g., 9082, 9084, and 9086shown in FIG. 9) located in the central hub of the radius limiter (e.g.,1016 shown in FIG. 1), when the radius limiter is nested with the basehousing 6012. Engaging arms 6088, 6090, and 6092 can be resilient andflex to engage with the radius limiter notches when assembled.

FIG. 7 is a bottom front perspective view of the modular optic fibercassette housing of FIG. 6 in accordance with one or more embodiments ofthe present disclosure. The external portion of mounting regions 6062,6064, 6066, and 6068 can include bosses 7069 that extend from the bottomsurface 7056 of the base housing 7012, providing additional material tosecure a screw used to attach an optical component into base housing7012 (see also FIG. 20). FIG. 7 also illustrates a bottom view of anchorpoints 7052 and 7056, showing the vertical offset away from the bottomsurface 7055 of the base housing 7012.

FIG. 8 is a top rear perspective view of the modular optic fibercassette housing of FIG. 6 in accordance with one or more embodiments ofthe present disclosure. As was similarly described with respect to FIG.6, base housing 8012 comprises a floor portion 8057, one or moresidewall portions 8058 substantially perpendicular to the internal floorportion 8057, and a front opening 8060 for receiving an adapter plate(e.g., 1014 shown in FIG. 1). Floor portion 8057 can include mountingregions 8062, 8064, 8068, and 8066, which may be raised regions orstandoffs as viewed from the inside of housing 8012.

Mounting regions 8062, 8064, 8066, and 8068 function to provide internalattachment points for optical components, if used, which are shown inFIG. 20 and discussed later. Mounting regions (e.g., 8062, 8064) can beconfigured to provide multiple attachment points so as to accommodate avariety of component sizes, configurations, and/or multiple mountingpositions; or provide a singular attachment point (e.g., 8066, 8068).Floor portion 8057 can also include bosses 8098 and 8100, for matingwith a radius limiter (e.g., 1016 in FIG. 1). FIG. 8 also illustrates atop view of anchor point 8054, showing the vertical offset away from thetop edge of the sidewall portion 8058 of the base housing 8012.

FIG. 9 is a top perspective view of a radius limiter in accordance withone or more embodiments of the present disclosure. As shown in FIG. 9,the radius limiter 9016 comprises base portion 9070 and central hub9072. Base portion 9070 comprises arcuate sides (e.g., 9076), whichgenerally provide an elongate shape.

Central hub 9072 includes notches 9082, 9084, and 9086 that mate witharms 8088, 8090, and 8092 of housing 8012, respectively, when assembledin base housing 8012 as shown in FIG. 8. Arms 8088, 8090, and 8092comprise hook portions at the end of each arm that engage with notches9082, 9084, and 9086, when assembled. Aims 8088, 8090, and 8092 arereleasable for disassembly. Arms 8088, 8090, and 8092 are resilient andflex to engage with notches 9082, 9084, and 9086 when assembled.Advantageously, the combination of arms 8088, 8090, and 8092 and notches9082, 9084, and 9086 provides easy assembly and disassembly of radiuslimiter 9016 with housing 8012 (shown in FIG. 8) embodiments of thepresent disclosure are not limited to the type of fastening apparatusillustrated in the accompanying drawings (e.g., arms 8088, 8090, and8092 and notches 9082, 9084, and 9086), and one or more embodiments ofcassettes may be configured to stabilize nested components using othertype fasteners, interference fits, or snap-fit structures, among others.

Radius limiter 9016 can include openings 9102 and 9106, that mate withbosses 8098 and 8100, respectively, of base housing 8012 when assembled.Radius limiter 9016 may also include additional (e.g., optional)openings to minimize the amount of material needed to fabricate radiuslimiter 9016.

FIG. 10 is a bottom perspective view of the radius limiter of FIG. 9 inaccordance with one or more embodiments of the present disclosure. FIG.10 illustrates a bottom view of notches 10082, 10084, and 10086, as wellas the underside of the base portion 10070 and central hub 9072.

Central hub 10072 of radius limiter 10016 is designed with a radius thatcorresponds with a predetermined minimum bend radius for a particularfiber being managed by a particular cassette (e.g., 1010 shown in FIG.1). Also, radius limiter 10016 is designed to be large enough to hold apre-terminated fiber assembly captive to surface 8057 of base housing8012 (see FIG. 8). When adapter plate (e.g., 1014) is exercised from thefront of a cassette (e.g., 1010), the radius limiter (e.g., 10016)functions to prevent fibers from having an unacceptably small radius orbend. Radius limiter 10016 also functions to prevent fibers from jumpingover radius limiter 10016 and possibly creating unacceptable micro bendscaused by pinch points resulting in radius violations.

FIG. 11 is a top front perspective view of a splice tray in accordancewith one or more embodiments of the present disclosure. FIG. 12 is abottom front perspective view of the splice tray of FIG. 11 inaccordance with one or more embodiments of the present disclosure, andFIG. 13 is a detail view of a portion of the splice tray of FIG. 11showing in particular a fiber nest and splice channels in accordancewith one or more embodiments of the present disclosure. Splice tray(e.g., 11018, 12018, and 13028) is shown in greater detail in FIGS.11-13.

Splice tray 11018 functions as a second level of fiber management withina cassette (e.g., 1010 in FIG. 1). As shown in FIG. 11, splice tray11018 provides a second level that is physically segregated from thefirst level of fiber management (e.g., base 6057 of housing 6012) inthat such surfaces are generally parallel. For additional physicalsegregation, splice tray 11018 may be covered within the cassette (e.g.,such as by cover 1020 shown in FIG. 1).

Splice tray 11018 comprises notches 11112, 11114, 11116, and 11118 thatcan engage with resilient releasable arms (e.g., 8120. 8122, 8124, and8126 shown in FIG. 8) to attach splice tray 11018 to housing 8012.Splice tray 11018 also includes raceways 11128 and 11130 that can beused to guide fibers within a cassette (e.g., 1010) between the firstlevel (e.g., base 6057 of housing 6012) and the second level (e.g., thesplice tray 11018) of a cassette (e.g., 1010). Raceways 11128 and 11130function as ramps and guides to help transition optical fiber betweenthe first and second levels.

Further referring to FIG. 11 in particular, splice tray 11018 can alsoinclude channel 11136 and openings 11138 and 11140 that function asentrances and/or exits for a fiber optic cable to enter or exit channel11136. Channel 11136 is defined in part by the back exterior wall of thesplice tray 11018 and channel wall 11137. Channel wall 11137 alsofunctions to support, in part, the splice tray cover (e.g., 1020 shownin. FIG. 1), which can rest upon the channel wall 11137. The raisedbosses shown incorporated into channel wall 11137 can additionally serveas a “snap down” point for mechanically attaching a splice tray cover(e.g., 1020 shown in FIG. 1) to the splice tray 11018.

Splice tray 11018 can be nested within the housing (e.g., 3012) suchthat a splice tray entry/exit opening 11130 receives a fiber optic cableprovided by base housing opening (e.g., 3024 in FIG. 3), and splice trayopening 11132 receives a fiber optic cable provided by entry/exitopening (e.g., 3026 in FIG. 3). Lacing points 11045 can be provided atrespective entry/exit openings of the raceways (e.g., 11130 and 11132),for example for securing the fiber optic cable, buffer tubes, orsubunits, such as with wax lace or zip ties.

Fiber nests 11132 and 11134 are provided for storing and managing coiledlengths of fiber within the splice tray 11018 when nested within acassette (e.g.. 1010). Fiber nest 11132 can include one or morehorizontal tabs 11142 that extend outwardly from vertical surfaces 11144to partially define a radial channel for helping to contain coiled fiberwithin splice tray 11018. Similarly, fiber nest 11134 can includehorizontal tabs 11146 that extend outwardly from surfaces 11148 topartially define a radial channel for helping to contain coiled fiberwithin splice tray 11018.

Splice tray 11018 also includes splice transition regions 11150 and11152, and one or more splice channels (e.g., 11154, 11155). Region11150 can include horizontal tabs 11156, which functions to guide fiberfrom nest 11132 to splice channels 11154, or from splice channels 11154to fiber nest 11132. Likewise, region 11152 can include horizontal tabs11158, which function to guide fiber to and from nest 11134 and splicechannels 11154. Splice channels 11154 function to hold splicing tubes inplace, both vertical and horizontally.

Splice tray 11018 includes a number of splice channels configured tohold splicing tubes and/or ribbon. For example, in the embodimentillustrated in FIG. 11 the splice tray 11018 includes six channels 11154configured to hold splicing tubes (e.g., six splice channels eachholding two splicing tubes) and one channel 11155 of a differentconfiguration (e.g., size, shape) to accommodate larger splice sleevesfor splicing ribbon. When two fibers are spliced together, a steel tubethat protects the delicate splice point can be used to encapsulate thesplice point. Heat shrink can be applied over the tube formoisture/humidity protection, with the tube being pressed down intochannels 11154. According to one or more embodiments of splice tray11018, two banks of channels 11154 are spaced apart so that a splicingtube can be accessed with fingers, or a tool. A splice tray cover (e.g.,1020 shown in FIG. 1) can be attached for added protection and retentionof fibers within splice tray 11018.

FIG. 12 illustrates a bottom front perspective view of a splice tray12018 in accordance with one or more embodiments of the presentdisclosure, showing an opposite perspective view of raceways 12128 and12130. The reader will appreciate the various cut-outs shown in thebottom of the splice tray, corresponding to the horizontal tabs (e.g.,11156, 11158, 11146, etc.) to aid in fabrication of the splice tray12018. FIG. 12 also shows the underside of lacing points 12045,illustrated in FIGS. 11 and 12 as being openings through the splice trayat respective entry/exit openings, the entry/exit openings correspondingto features of the base housing for outing fibers to/from the basehousing and the splice tray.

FIG. 13 provides a close-up view of a fiber nest portion of a splicetray 13018, further illustrating raceway 13130, notch 13116, channel13136, channel wall 13137, opening 13140, vertical surfaces 13144,horizontal tabs 13144, and notch 13118 as previously describe withrespect to corresponding features shown in preceding figures inaccordance with one or more embodiments of the present disclosure.

FIG. 14 is a top front perspective view of a modular optic fibercassette housing cover in accordance with one or more embodiments of thepresent disclosure, and FIG. 15 is a bottom front perspective view ofthe modular optic fiber cassette housing cover of FIG. 14 in accordancewith one or more embodiments of the present disclosure housing cover(e.g., 14022 in FIG. 14, 15022 in FIG. 15) is shown having one or moreresilient releasable arms (e.g., 15160, 14164 shown in FIG. 14corresponding to 15164 shown in FIGS. 15, and 15162) that engage withnotches 8166, 8168, and 8170 shown in FIG. 8, respectively, of basehousing 8012 seen in FIG. 8. Housing cover 15022 also serves to hold theMTP/MPO adapters (e.g., 4036 and 4038 shown in FIG. 4 of cassette 4010.Housing cover (e.g., 14022, 15022) also engages with strain relief tubes(e.g., 5028 and 5030 shown in FIG. 5) to provide strain relief and bendradius protection for fragile incoming buffer tubes.

FIG. 16 is a front perspective view of a modular optic fiber cassettehousing having a radius limiter nested in the optic fiber cassettehousing with plural fibers (partial view) connected to an adapter plateand looped around the radius limiter in accordance with one or moreembodiments of the present disclosure. FIG. 16 illustrates aconfiguration that can be used for patch only applications wherecassette 16010 utilizes a housing 16012, radius limiter 16016 (forradius protection when adapter plate 16014 is extended away from thehousing 16012), and a housing cover (e.g., 1022 in FIG. 1—not shown inFIG. 16).

Inside base housing 16012, fibers are connected on one end to connectors16017, which are mounted on the detachable the adapter plate 16014.Fibers 16174 collectively form a fiber loop 16172, which is slack storedon the lower level of cassette 16010, the fiber loop 16172 being routedaround radius limiter 16016. As previously discussed, radius limiter16016 includes a central hub (e.g., 10072 in FIG. 10) having a diametersized to limit the minimum radius of fiber loop 16172 for protectionthereof, when for example, adapter plate 16014 is removed therebypulling on fiber loop 16172 and reducing its slack. For patch onlyconfigurations (illustrated in FIGS. 16 and 17), fiber loop 16172 isrouted and tied off, for example, just before a transition of themulti-fiber buffer tube (or subunits) to individual (e.g., discrete)fibers.

For added modularity, cassette 16010 supports MPO assemblies andadapters on the rear side of cassette 16010. Twelve industry standardterminations to twelve-fiber MPO ribbon terminations inside cassette16010 provide a fully self-contained interconnect environment formodularity. MPO pre-terminated distribution or outside plant cables inall constructions and fiber counts are supported allowing for abuild-a-panel environment that allows for quicker delivery times andrapid service turn-up in the field.

FIG. 17 is a front perspective view of a modular optic fiber cassettehousing having an adapter plate extended away from the optic fibercassette housing in accordance with one or more embodiments of thepresent disclosure. Adapter plate 17014, including internal connectors17017, can be detached from base housing 17102 of cassette 17010, andmoved in a direction indicated by arrows 17072 (e.g., away from the basehousing 17012). The fibers 17174 attached to the internal connectors17017 pull fiber loop 17172 tighter around radius limiter 17016, as canbe seen in FIG. 17 compared to FIG. 16. Fiber loop 17172 includes enoughslack to permit the adapter plate 17014, which is releasable from thebase housing 17012, to be pulled far enough away from base housing 17012to permit access to both sides of the adapter plate 17014, includinginternal connectors 17017 (e.g., without removing cassette 17010 from arack (not shown) upon which it may be secured by its flange). Providingaccess to both sides of the adapter plate 17014, including to externalconnectors 1015 shown in FIG. 1 and internal connectors 17017, whilecassette 17010 is secured into a rack is beneficial for ease ofinstallation, maintenance, and cleaning. This ease of access alsoreduces the risk of fiber damage to adjacent cassettes in a fibermanagement housing (e.g., rack mount). The releasable adapter plate17014 minimizes movement of individual fibers that may occur in previousapproaches.

FIG. 18 is a front perspective view of a modular optic fiber cassettehousing having a pre-loaded splice tray nested in the optic fibercassette housing in accordance with one or more embodiments of thepresent disclosure. FIG. 18 illustrates a configuration that can be usedfor a patch and splice applications where cassette 18010 furtherincludes a splice tray 18018 nested within base housing 18012. FIG. 18illustrates how fiber can be routed from the base housing 18012 to thesplice tray 18018, since the fiber loop 17172 shown in FIG. 17 in thebase housing continues on to become fiber loop 18172 in the splice tray,as illustrated in FIG. 18.

Patch and splice applications for cassette 18010 utilizes base housing18012, radius limiter (not visible in FIG. 18 since nested below splicetray), splice tray 18018, and housing cover (e.g., 1022 in FIG. 1—notshown in FIG. 18 so that internal components of cassette 18010 arevisible). The splice tray 18018 nests atop of, and rests upon, theradius limiter (e.g., 17016 shown in FIG. 17, if installed, which inturn is supported by its central hub (e.g., 9072 shown in FIG. 9) andbosses (e.g., 8098 and 8100 shown in FIG. 8) extending from the floor8056 of the base housing 8012, as shown in FIG. 8. Bosses (e.g., 8098and 8100) extend through the radius limiter (e.g., 17016) viacorresponding holes (e.g., 9102 and 9106) therethrough, such that thesplice tray can rest upon, and be supported by, the bosses. For cassetteconfigurations not utilizing the radius limiter (e.g., 17016), thesplice tray 18018 can still rest upon, and be supported by, the bosses(e.g., 8098 and 8100 shown in FIG. 8).

A front portion of the splice tray 18018 can also rest upon, and besupported by, one or more stand-offs 18061. Stand-offs 18061 are shownbeing located under the front corners of the splice tray 18018 formaximum side-to-side and front-to-back stability. In working with thefiber splices, located near the front portion of the splice tray (e.g.,nearest the adapter plate), technicians can exert vertical force down onthe front portion of the splice tray in attempting to seat splices andbuffer tubes into the splice tray. Thus, having adequate support underthe front of the splice tray is advantageous in protecting individualfibers that run beneath the splice tray to the connectors of the adapterplate.

While two bosses, and two stand-offs are illustrated in the presentdisclosure, embodiments of the present invention are not restricted tothese respective quantities. The reader will appreciate that threepoints arranged in space define a plane, and three support locations canprovide reasonable mechanical stability of a planar device. According toone or more embodiments, the splice tray is supported in the basehousing atop the radius limiter by at least one boss extending from thebase housing through the radius limiter, and by at least one stand-offextending from the base housing not through the radius limiter, the atleast one boss and at least one stand-off defining a plane upon whichthe splice tray rests. For example, according to one or moreembodiments, a single stand-off may be centrally located to support thefront portion of the splice tray, along with the two bosses that supportthe radius limiter. In some embodiments, stand-offs may be located underother portions of the splice tray.

Cassette 18010 does not restrict space when splicing is required, andeliminates the need for twelve-fiber tight-buffered slack storage thatrequires additional space outside of traditional fiber managementproducts. Cassette 18010 allows for up to one meter of tight-buffered900-micron assemblies pre-terminated and pre-loaded and slack-storedinside of cassette 18010. OSP fiber cable can be brought directly to oneor more cassettes 18010 for splicing. Slack storage space forbuffer-tube-only applications minimizes space needed for storage andeliminates congestion, and cable lock-in as tight buffered cables arenot stored in the same routing space.

Space allocation can be done in advance of arrival of splicingtechnicians. Cassette 18010 can be handled the same was as a traditionalsplice tray is handled but with added benefit of a terminated assemblyalready attached. Cassette 18010 also supports traditional off-framesplicing and on-frame splicing applications, using separate splicedecks.

For patch and splice configurations (illustrated), fiber loop (e.g.,16172 shown in FIG. 16) is tight buffered and is routed from the lowerlevel of cassette 18010 to the second level of the cassette 18010 (e.g.,the splice tray 18018) via splice tray ramp 18128, with additional fiberslack stored within fiber nest 18134. The opposite ends of fibers (e.g.,16174 shown terminated to internal connectors 16017 in FIG. 16) can bepositioned for splicing in splice channels 18154 (e.g., two per eachchannel 18154) lip to one half meter of slack storage is available fromthe upper and lower levels of the illustrated cassette 18010, includingin the base housing 18012 and splice tray 18018. However, embodiments ofthe present disclosure are not limited to this amount of slack storage,and cassettes may be configured to provide more, or less, slack storagecapability (e.g., volume).

FIG. 19 is a front perspective view of a modular optic fiber cassettehousing having a splice tray nested in the optic fiber cassette basehousing 19012 in accordance with one or more embodiments of the presentdisclosure. In the field, a buffer tube 19176 is routed into thecassette 19010 through strain relief tube 19026, which provides bendradius protection. Fiber optic cables can be secured in place, forexample, by fastening them to lacing points using zip ties or lacingcord. The buffer tube 19176 can be routed such that slack is stored infiber nest 19132, and broken out into individual fibers 19178, which inturn are spliced with fibers (e.g., 18154 shown in FIG. 18) to formsplices 119180 that are positioned in splice channels (e.g., 18154) ofthe splice tray (e.g., 18018 shown in FIG. 18).

In one or more patch and splice applications, cassette 19010 can bepre-loaded with a 12-fiber assembly of 900 micron individual fibercircuits terminated to twelve connectors that are mated to connectors(e.g., 17017) on adapter plate (e.g., 17014). A user would then bring anOSP (outside the plant) or IFC (intra-facility cable) cable that iseither a buffer tube (OSP) or subunit (IFC) of 12-fibers that has beenbroke from an overall jacket housing a number of subunits (e.g., buffertubes). For example, a 144 fiber cable has 12 subunits (distribution) orbuffer tubes (OSP) inside an overall jacket. A 96 fiber cable has eightsubunits or buffer tubes of 12 fibers each, etc. The particular fibercable is spliced to pre-terminated (e.g., pre-loaded) fiber assembliesinside a cassette (e.g., 18010) via splice tray 18018. The fibers can bebroken out by buffer tubes therein, with each buffer tube beingterminated to one of a number of cassettes needed to equal the totalfiber count of the cable divided by twelve. For example, a 144 fibercable can be terminated into twelve pre-loaded cassettes.

Referring back to FIG. 1, adapter plates (e.g., 1014) support industrystandard connectors on interconnect field. The feeder field supports avariety of cable constructions in addition to multi-fiber ribbonconnector MPT/MPO. The feeder field is the fiber optics coming from acentral office or where content is being generated and then sentdownstream to a patch panel or cabinet in the field. The distributionfield or network points downstream to the end user or subscriber such asa home or business. The interconnect functions occur when the feedernetwork is physically connected or mated to the distribution network(e.g., through cassettes 1010). For example, a cassette 1010 that hasbeen terminated with a cable that is coming from a central office wouldhave a patch cord mated to one of connectors 1015 of which the other endis mated to another connector 1015 on a different cassette 1010 that hasbeen terminated with a cable that is pointing downstream to the enduser.

For patch only configurations cassette 1010 can be pre-loaded withdistribution or OSP tight-buffered constructions including ribbon andbreakout style cables. Multi-fiber counts above twelve can be supportedwith multi-cassette configurations. Cassette 1010 supports pluralentry-exit points and cable tie-offs including integrated grommetstrain-relief for delicate constructions.

FIG. 20 is a front perspective view of a modular optic fiber cassettehousing having a modular optical component nested in the optic fibercassette housing in accordance with one or more embodiments of thepresent disclosure.

Base housing 20012 can include a number of mounting regions (e.g.,20066, 20068), as previously discussed with respect to FIG. 8, which canbe used to mount the modular optical component 20067 inside the basehousing 20012. Depending on the function and configuration of themodular optical component 20067, connections may be routed to theconnectors of the adapter plate 20014, among other locations.

Base housing 20012 can accept optical components such as FBT (fusedbiconic taper) and planar lightwave circuit (PLC) splitters in eithertube style, and cassette packaging, among others. Additionally, wavedivision multiplexers for both coarse and densewave applications can beintegrated. Single height cassettes support optical componentscomprising twelve combined input/output interfaces. Double and tripleheight cassettes (e.g., having expansion housings—discussed below)support any configuration or applications that exceeds twelve combinedinput/output interfaces.

As illustrated in FIG. 20, various optical components (e.g., wavesplitters, signal branches, couplers, WDM's, CWDM's, DWDM's, amongothers) can be operatively positioned within base housing 20012. Amodular optical fiber cassette, including base housing 20012, canadvantageously function as a fiber management device and an opticalcomponent chassis or hybrid chassis that supports both a predeterminednumber of terminated ports and optical component hardware. Higher portcounts of splitters such as 1×16, 1×32, and 1×64 split counts areadvantageously supported in 2, 3, and 6 high cassettes 10.

Any combination of mounting regions (e.g., 6062, 6064, 6066, and 6068 asshown in FIG. 6) can be used to mount an optical component. In someembodiments, a bracket (not shown) can be attached to one or more ofmounting regions having multiple bosses (e.g., 6062 and 6064 as shown inFIG. 6). The bracket Can be used to secure the optical component. In oneor more embodiments, an optical component can be directly attached tothe mounting regions using one or more fasteners into the multiplebosses (e.g., 6062 and 6064 as shown in FIG. 6). In other embodiments,all mounting regions (e.g., 6062, 6064, 6066, and 6068 as shown in FIG.6) are used to secure large optical components (e.g., optical componentshaving a large number of input/output legs, such as those packaged in a10 mm×80 mm×100 mm package).

FIG. 21 is an exploded perspective view of a modular optic fibercassette including a housing base and housing extender in accordancewith one or more embodiments of the present disclosure. The cassette21011 illustrated in FIG. 21 is similar to the cassette 1010 shown inFIG. 1, with the addition of an expansion housing 21013. Modular opticalfiber cassette 21011 (hereinafter “cassette”), as shown, comprises abase housing 21012, adapter plate 21014 (including a plurality ofexternal connectors 21015 and internal connectors 21017), expansionhousing 21013, radius limiter 21016, splice tray 21018, splice traycover 21020, and housing cover 21022. Adapter plate can be attached tobase housing 21012 by one or more quick-release fasteners 21040, andbase housing 21012 can be attached and/or mounted to a rack (not shown)by fasteners 21041 (e.g., screws) through opening 21043-B in tab 21050-B(“B” indicates “base,” similar features on expansion housing areindicated by similar reference numbering followed by “E” indicating“expansion”). Similarly, expansion housing 21013 can be attached and/ormounted to the rack (not shown) by similar fasteners through opening21042-E in tab 21044-E.

While cassette 21011 is shown in FIG. 21 as including all of theabove-mentioned components, embodiments of the present disclosure arenot so limited, and a particular cassette 21011 may be assembled toinclude additional components not shown in FIG. 21, or less than all thecomponents illustrated in FIG. 21, depending on a particular applicationfor cassette 21011.

FIG. 22 is a top front perspective view of a modular optic fibercassette 22011 including a housing base 22012, an expansion housing22013, and a cover 22022 in accordance with one or more embodiments ofthe present disclosure, and FIG. 23 is a top rear perspective view of amodular optic fiber cassette 23011 of including a housing base 23012 andexpansion housing 23013 in accordance with one or more embodiments ofthe present disclosure. Expansion housing 23013 includes a faceplate22009 above the opening in base housing 22012 located to receive theadapter plate 22014. When a cassette 22011 includes an expansion housing22013, the cover 22011 is attached to the expansion housing 22013 ratherthan the housing base 23012.

A cassette (e.g., 22011 in FIG. 22 and/or 23011 in FIG. 23) can includea number of anchor points (e.g., right side anchor point 22056-B on basehousing 22012 shown in FIG. 22, right side anchor point 22056-E inexpansion housing 22013 shown in FIG. 22, left side anchor point 23052-Bon base housing 23012 shown in FIG. 23, left side anchor point 23052-Ein expansion housing 22013 shown in FIG. 23, rear anchor point 23054-Bon base housing 23012 shown in FIG. 23, and rear anchor point 23054-E inexpansion housing 23013 shown in FIG. 23).

The anchor points can be used to gang (e.g., group) cassettes (includingbase housing and expansion housings) together into one block for easierinstallation and shipping. As the cassettes are modular, each having acapacity to handle units of 12 fibers, the quantity of cassettes may beselected to accommodate a presently used fiber count, and subsequentlymodified to accommodate a different future fiber count. For example, a288-port cabinet may he initially loaded with 144 ports (e.g., less thanthe full capacity of the cabinet) using 12 cassettes, each cassetteterminating 12 fibers. If in the future there is a need for additionalfiber capacity in the cabinet, a number of pre-terminated cassettes(e.g., 12 cassettes, each terminating 12 fibers, for a total of anadditional 144 fibers) can be added to the cabinet. The 12 new cassettescan be ganged (e.g., fastened together) into a solid block for easierinstallation and handling.

Cassettes may configured to be single height (e.g., comprising just abase housing and no expansion housing), or configured to be an expandedheight by utilizing one or more expansion housings (e.g., 23013). WhileFIGS. 22 and 23 illustrate cassettes 22011 and 23011 as including asingle expansion housing (e.g., 22013 and 23013 respectively),embodiments of the present disclosure are not so limited, and mayinclude one or more expansion housings: Furthermore, some anchor points(described above) may be used to join all cassettes of a group togetherinto a block, or join all expansion housings of a particular cassette toits base housing, or some combination thereof.

FIG. 23 illustrates that base housing retains an opening 23024 for astrain relief tube (e.g., 5028 shown in FIG. 5), similar to opening 3024shown in FIG. 3, however, the top portion of the opening is completed bythe expansion housing 23013, rather than the by cover 23022. Basehousing also retains an opening 23032 for a connector (e.g., 4036 shownin FIG. 4), similar to opening 3032 shown in FIG. 3, however, the topportion of the opening is completed by the expansion housing 23013,rather than the by cover 23022.

FIG. 24 is a top front perspective view of a modular optic fibercassette expansion housing 24013 in accordance with one or moreembodiments of the present disclosure, FIG. 25 is a bottom frontperspective view of a modular optic fiber cassette expansion housing25013 in accordance with one or more embodiments of the presentdisclosure, and FIG. 26 is a top rear perspective view of a modularoptic fiber cassette expansion housing in accordance with one or moreembodiments of the present disclosure. The reader will appreciate thatone or more expansion housing may be used to increase the height of aparticular cassette, thereby creating more volume inside and allowingadditional fiber storage or additional component modules, or componentmodules of increased height, etc.

Expansion housings (e.g. 24013, 25013, 26013) comprise a cassette shellwall, but having two opposing sides (e.g., top and bottom) being open,so as to provide additional cassette volume to the base housing (e.g.,21012 shown in FIG. 21) corresponding to the base housing footprint. Forreference, anchor points (e.g., right anchor point 24056-E shown in FIG.24, left anchor point 25052-E and right anchor point 25055-E shown inFIG. 25, and left anchor point 26052-E shown in FIG. 26 are shown on theexpansion housings (e.g., 24013, 25013, and 26013). The expansionhousing can include tabs (e.g., 24055-E, 25055-E, 25057-E, 26055-E, and26057-E) for mating with a base housing (e.g., 23012 in FIG. 23) oranother expansion housing when more than one expansion housing is usedfor a particular cassette. The expansion housing can also include guidepins (e.g., 25059 and 26059) and corresponding guide pin receptacles(e.g., 24051 and 26051) to provide support and alignment with expansionhousings.

FIG. 27 is a optic fiber communication system in accordance with one ormore embodiments of the present disclosure. FIG. 27 illustrates an OSPfiber optic feeder 27002 from a central office 27001 to distributionstructure 27003. A fiber entrance cabinet (FEC) may be located at thecentral office 27001 (e.g., head end) typically in an off-frame splicingenvironment. From the distribution structure 27003, OSP distributionfiber cable 27004 are routed to drop structures 27005, such as a fiberdistribution pedestal, which can serve as a final interconnection pointin a fiber to the home (FTTH) network before reaching a particularfiber's end user location (e.g., a home). Fiber downstream of the fiberdistribution pedestal to the end user location is commonly referred toas “the last mile” regardless of actual distance involved. One or moreindividual drop fibers 27009 are routed from the drop structure 27005 toend users, such as residential 27008, commercial 27006, and/ormulti-unit dwelling 27007 users.

Building a FTTH network is a labor-intensive effort. A significantportion of this labor is associated with the hours it takes a splicecrew to perform the tedious work of splicing each individualin-ground/distribution cable to the passive optical network (PON)cabinet. Critical to the control of operational and capital costcontrols is a standard splicing methodology that guarantees a timely,quality burn. The splicing of feeder and distribution network fibers toa FTTH-PON cabinet is traditionally done in a splice closure. Theenclosure is installed below grade in a handhole directly beneath thecabinet or in a splice vault near the cabinet. The cabinet is preloadedwith a factory terminated OSP stub and enough slack, stored in thehandhole or splice vault, to allow for the splicing crew to pull boththe cabinet stubs and the in-ground feeder/distribution cables out to adesired area. For comfort, convenience and cleanliness, the best placeto perform this tedious work is within a controlled environment like asplice trailer. To allow for this convenience, it is not unusual forstubbed lengths to reach 500 feet.

In an effort to reduce costs (and because in some harsh environmentallocations the use of a below grade handlhole or splice vault was notpossible), some outside plant planners instituted network designs thateliminated the use of the handhole (or splice vault) and incorporatedthe splicing directly inside of the cabinet. A patch and splice cabinettypically incorporates hardware within the cabinet to perform cablepreparation, cable slack storage and splicing. However, this approachpresents trade-offs. The user, because pre-terminated slack storagewithin the cabinet is limited, is forced to perform splicing activitieswithin close proximity of the cabinet. Often, this distance is 15 feetor less. This is usually not enough distance to use the desiredcontrolled environment splice trailer.

The result is that splicing was being done in open-air environments, notconducive to a quality splice. As an alternative, in an effort to getsplicing crews out of an open air environment, other network plannersordered the stubbed lengths of jacketed tight buffered cable at thetraditionally longer lengths which created additional undesirableconditions: 1) Longer lengths of distribution style tight bufferedcables not necessarily designed for OSP environments and, 2) Largercabinet sizes to accommodate and safely store slack which limiteddensity of the cabinet and footprint it could satisfy.

In PON environments the present disclosure allows network engineers toenjoy the cost savings of patch and splice without the historicaltrade-offs. Fiber management cassettes and methods in accordance withthe present disclosure each provide a complete, cost effective, andturnkey fiber management solution. Advantageously, fiber is protected insub-units of 12 fibers, Jacketed cable storage is thus eliminatedbecause the 900 micron tight buffers have shed the outer riser-ratedjacket in favor of the cassette that protects it not only from humanaccidental damage but also provides bend radius protection. Byeliminating the requirement for jacketed fiber, fiber managementcassettes and methods in accordance with the present disclosureaccommodate fiber management needs plus the slack storage required for a288 home served configuration in just 4 cubic feet of cabinet space.Further, due to the nesting and modular design of the fiber managementcassettes of the present disclosure, splice trays are integrated intothe protection of the cassette itself, eliminating the need forspace-consuming (and expensive) splice closures. The splicing solutionis thus portable. The user can now pull feeder/distribution cablesthrough the cabinet and as far as OSP slack allows to the splicetrailer. Advantageously, the user does not have to manage, at the sametime, an OSP tail (from the cabinet) of equal length. The number ofsplice trays are matched to the cable counts and advantageously nestedwithin fiber management cassettes of the present disclosure.

Advantageously, a user can splice pre-terminated fiber managementcassettes to the network fiber inside a controlled environment. Toaccommodate high-density environments and/or high fiber counts, fibermanagement cassettes can be ganged or grouped together allowing thesplicer to move from 12 to 288 fibers at a time. This allows the user tosplice one sheath at a time matching the OSP fiber count to a gangedcassette block without having to manage capacity and entry/exit portsassociated with a splice closure.

A ganged block of fiber management cassettes in accordance with thepresent disclosure eliminates further costs in the splice closure thatwould have traditionally been used in a patch only environment. Thecosts of a splice closure loaded with splice trays, slack baskets, andthe risk of an un-sealed closure in time can be eliminated. Furthermore,the cumbersome tasks in network design to match cable sheaths and fibercounts inside the closure and the hassle of splitting buffer tubes canbe eliminated because the user's cable sheaths will always match theblock of fiber management cassettes.

Fiber management cassettes and methods in accordance with the presentdisclosure can provide cost savings that are gained without having tosacrifice the ease and convenience of a patch only installation. Whatthe user ends up with is an ultra modular fiber management systemwherein feeder/distribution ratios are scalable at a user-defined 12fibers at a time. Fiber management cassettes in accordance with thepresent disclosure provide a patch and splice system that can be usedlike traditional patch only but has eliminated costs associated withjacketed fiber, the space that was traditionally allocated to store theterminated slack, the cost of a splice case sitting below the cabinet inthe handhole, and the size of the handhole necessary because no splicevault is used.

Any optical circuit that is being touched or that is moving ispotentially at risk of damage. Thus, solutions that minimize touchingand/or moving such circuits are preferred. Fiber management cassettesand methods in accordance with the present disclosure advantageouslyreduce the number of touches, re-routes, and the amount of moving fiber.Two areas of fiber management of particular interest are the splitterparking lot and swinging bulkheads.

Fiber management cassettes and methods in accordance with the presentdisclosure minimize risk of damage to the splitter module as cassettescan be pre-parked within a disposable, parking block, enabling the userto simply place the splitter into the splitter cage, route thepre-parked jumpers up to the parking block storage area and deploysubscriber circuits from there. This deployment methodology enables themajority of the final destination of each output leg to be touched onlyonce. As subscribers are turned up, each leg is routed to the requiredport without having to remove a jumper from a bundle of live circuits.

Swinging bulkheads can provide ease of access, but swinging bulkheadshave drawbacks. In certain swinging bulkheads it is possible to have288, 576, or 576 delicate 900-micron fibers moving all at once.According to one or more embodiments of the present disclosure, fibermanagement is designed to minimize the risk on both sides of the adapterfrom the feeder to the distribution network. This is true whether asplitter output circuit is parked or in-service. This is especially truefor multifiber OSP cables whose buffer tubes have been exposed andremoved from the very material designed to protect it and allowed tomove with every bulkhead opening.

FIGS. 28A-28E illustrate an optical fiber management housing 28010 in afolded and an unfolded configuration in accordance with one or moreembodiments of the present disclosure. In one or more embodiments, andas illustrated in FIG. 28A, the housing 28010 can include a number ofpanels coupled together via living hinges 28115. As used herein, a“living hinge” refers to a flexible hinge that joins plastic partstogether allowing them to bend along the line of the hinge. A livinghinge can be manufactured as a single part (e.g., in an injectionmolding process that creates the parts to be joined by the living hingeand the living hinge itself). As such, providing an optical managementhousing with living hinges can allow the housing to be made as onecontinuous part, or non-separably joined parts that can repeatedly movebetween at least two distinct positions and geometries without breakingor part failure.

A living hinge can be made of various materials having suitable fatigueresistance, which can allow the hinge to remain functional over the lifeof the single part in one or more embodiments, a living hinge can bemade of a polypropylene material. The polypropylene can be an impactpolypropylene or high impact polypropylene (HIPP), among otherpolypropylene materials. Embodiments are not limited to living hingesmade of a particular material. For instance, a living hinge can be madeof a polyethylene material or other material having suitable fatigueresistance properties.

In the embodiment illustrated in FIG. 28A, the optical fiber managementhousing 28010 is shown in a first configuration (e.g., an unfolded orunassembled configuration) and includes a base panel 28108, a first sidepanel 28112-1, a second side panel 28112-2, a third side panel 28112-3,and a cover panel 28110. As shown in FIG. 28A, the first (28112-1),second (28112-2), and third (28112-3) side panels are each coupled tothe base panel 28108 via a respective living hinge 28115. For instance,the first side panel 28112-1 is coupled to the base panel 28108 via afirst living hinge 28115-1, the second side panel 28112-2 is coupled tothe base panel 28108 via a second living hinge 28115-2, the third sidepanel 28112-3 is coupled to the base panel 28108 via a third livinghinge 28115-3. Also, in the embodiment illustrated in FIG. 28A, thecover panel 28110 is coupled to the third side panel 28112-3 via afourth living hinge 28115-4. As illustrated in FIG. 28A, the third andfourth living hinges 28115-3 and 28115-4 are on opposite sides of thethird side panel 28112-3 and define the geometry of the third side panel28112-3. The third and fourth living hinges 28115-3 and 28115-4 can bereferred to as a bottom hinge 28115-3 and top hinge 28115-4 when thehousing 28010 is in a second configuration (e.g., a folded or assembledconfiguration) as described further below. In one or more embodiments,the base panel 28108, first side panel 28112-1, second side panel28112-2, third side panel 28112-3, cover panel 28110, and correspondingliving hinges 28115 can be manufactured together as a single unit (e.g.,via an injection molding process).

In one or more embodiments, the housing 28010 can include one or moreoptical management components integrally formed on the base panel 28108.For instance, in the embodiment illustrated in FIG. 28A, base panel28108 includes a splice tray 28105 integrally formed thereon. As such,in this embodiment, the optical management component (e.g., splice tray28105) is formed of the same material as the base panel 28108 (e.g.,polypropylene). The splice tray can include a number of splice channels28154. In various embodiments, the splice tray 28105 can include asplice tray cover (e.g., cover 1020 shown in FIG. 1) releasablyconnected to the splice tray.

Embodiments are not limited to a particular optical managementcomponent. For instance, in one or more embodiments, the base panel28108 can include one or more mounting components (e.g., mountingcomponents 6062, 6064, 6066, and 6068 shown in FIG. 6 and mountingcomponents 8062, 8064, 8066, and 8068 shown in FIG. 8) integrally formedthereon. The mounting components can function to provide internalattachment points for other optical components such as wave splitters,signal branches, couplers, WDM's, CWDM's, DWDM's, among various othersoptical components.

In various embodiments, and as illustrated in FIGS. 28A and 2813, thehousing 28010 can include one or more openings through which opticalfibers can enter and/or exit the housing 28010. For instance, in theembodiment illustrated in FIGS. 28A and 28B, the openings 28024 formedin the first, second, and third side panels can be combined (e.g., in afolded configuration shown in FIGS. 28C-28E) and configured to receive astrain relief tube (e.g., a strain relief tube as illustrated above inconnection with FIGS. 5 and 19) and/or other component that can be usedto protect optical fibers associated with the housing 28010.

In the embodiment illustrated in FIG. 28A, the housing 28010 includes afirst adapter plate 28014-1 and a second adapter plate 28014-2temporarily attached to the cover panel 28110. As described furtherbelow, the adapter plates 28114-1 and 28114-2 are configured to bedisconnected from the unfolded configuration of housing 28010. Upondisconnection from the cover panel 28110, the adapter plates 28014-1 and28014-2 are configured for releasable connection to the housing 28010 inthe second (e.g., assembled) configuration. That is, the adapter plates28014-1 and 28014-2 function as removable adapter plates for releasableconnection to the housing 28010 as shown in FIGS. 2813, 28C, and 28D. Asillustrated in FIG. 28A, the adapter plates 28014-1 and 28014-2 eachinclude a number of apertures 28127 therein. The apertures 28127 areconfigured to receive a corresponding number of external opticalconnectors (e.g., optical connectors 28015 shown in FIGS. 2813, 28C, and28D or optical connectors 1015 shown in FIG. 1). The number of externaloptical connectors are configured for attachment to a correspondingnumber of internal optical connectors (e.g., 1017 shown in FIG. 1)coupled to a corresponding number of optical fibers (e.g., fibers 16174and 17174 shown in FIGS. 16 and 17, respectively). In the embodimentillustrated in FIGS. 28A-28D, the adapter plates 28014-1 and 28014-2each include six apertures to accommodate six optical connectors (e.g.,the housing 28010 is a six-port housing). Embodiments are not solimited. For instance, the adapter plates 28014-1 and 28014-2 can beconfigured to accommodate more or fewer than six optical connectors, andthe adapter plates 28014-1 and 28014-2 may each include a differentnumber of apertures 28127.

In the embodiment illustrated in FIG. 28A, the housing 28010 alsoincludes a number of snap in plugs 28137. The plugs 28137 are attachedto the cover panel 28110 and can be removed (e.g., disconnected) andplaced within one or more unused connector ports(e.g., one or more ofports 28127 that does not receive an optical connector or a port 28117shown in FIG. 28E).

In various embodiments, the housing 28010 can be easily convertedbetween a first unfolded (unassembled) configuration (e.g., asillustrated in FIGS. 28A and 28B) and a second folded (assembled)configuration (e.g., as illustrated in FIGS. 28C-28E). For instance, toconvert the housing 28010 to the folded configuration, the base panel,the first, second, and third side panels, and the cover panel can bereleasably connected together to form an assembled optical fibermanagement housing 28010. The removable adapter plates 28014-1 or28014-2 can each be releasably connected to the housing 28010 so as toform a fourth side panel of the housing 28010 when in the assembledconfiguration as shown in FIGS. 28C and 28D.

When in the folded configuration as shown in FIG. 28C the housing 28010can provide a compact geometry. In one embodiment, the assembled housing28010 is about four inches wide, about one inch high, and about fiveinches deep. In one or more embodiments, the dimensions of the housing28010 can correspond to a particular standard, such as an LOX (lightguide cross-connect) standard, among others. For instance, the adapterplate 28014-2 includes mounting apertures 28131 spaced to correspond toan LGX standard. As such, the appropriate adapter plate (e.g., 28014-1or 28014-2) can be selected based on a desired standard or a particulardimension.

Although embodiments are not limited to particular dimensions, one ormore embodiments having the compact geometry described above for theassembled housing 28010 can provide various benefits. For instance, someoptical fiber management applications require a low number of fibers(e.g., 1 to 6), and thus only need the complement number of apertures28127 (e.g., ports) to accommodate an associated number of opticalconnectors in such cases, providing an optical fiber management housingwith a larger count of apertures to accommodate an associated number ofoptical connectors can unnecessarily create a larger optical fibermanagement housing geometry (e.g., footprint) and come with associatedadditional cost in material and complexity than are intended for aparticular implementation, which, can be cost prohibitive for acustomer. Also, providing a housing with a small footprint, such as thatshown in FIGS. 28C and 28D, can allow the housing (e.g., 28010) to beeasily mounted in various locations or to fit within and/or be mountedwithin a variety of protective enclosures (e.g., metal or plasticenclosures).

As illustrated in FIGS. 28C and 28D, the adapter plates 28014-1 and28014-2 are configured to be releasably connected to the base panel28108, the cover panel 28110, and/or one or more of the first, second,and third side panels (e.g., the two side panels 28112-1 and 28112-2 asshown in FIGS. 28C and 28D). In one or more embodiments, and asillustrated in FIGS. 28A-28D, releasable connection of the variouspanels to convert the optical fiber management housing 28010 between theassembled (folded) and unassembled (unfolded) configurations isaccomplished via a number of tabs 28120 and corresponding tab receivingopenings 28121. For instance, each of the base panel 28108, cover panel28110, first side panel 28112-1, second side panel 28112-2, third sidepanel 28112-3, and adapter plates 28014-1 and 28014-2 can include atleast one tab 28120 and/or at least one tab receiving opening 28121. Asillustrated in FIG. 28A, when the housing 28010 is in the unfoldedconfiguration, the base panel, cover panel, and first, second, and thirdside panels can all be oriented in the same plane (e.g., a horizontalplane). In one or more embodiments, when the housing 28010 is in theunfolded configuration, the base panel, cover panel, and first, second,and third side panels can all be oriented substantially within one plane(e.g., about 45 degrees or less from a particular plane). Embodimentsare not so limited. For instance, in one or more embodiments, thehousing 28010 can be considered to be in an unfolded configurationwhenever one or more of the cover panel, and first, second, and thirdside panels are positioned so as to allow access to an interior of thehousing (e.g., to allow access to optical component 28105). Forinstance, the housing 28010 illustrated in FIG. 28C is in an unfoldedconfiguration (e.g., a configuration between the unfolded configurationshown in FIG. 28A and the folded configuration shown in FIGS. 28C and28D).

In one or more embodiments, converting the housing 28010 from theunfolded to the folded configuration can include first folding (e.g.,via a living hinge 28115) the first side panel 28112-1 and the secondside panel 28112-2 from a horizontal unfolded position (e.g., as shownin FIG. 28A) to a vertical folded position (e.g., as shown in FIGS. 28Cand 28D) such that the side panels 28112-1 and 28112-2 are in a planesubstantially perpendicular to the plane in which the base panel 28108resides. Next, the third side panel 28112-3 (along with the cover panel28110) can be folded from the horizontal unfolded position to a verticalfolded position in this example, the tab receiving openings 28121 in thethird side panel 28112-3 would receive the corresponding tabs 28120 onthe back ends of the respective first side panel 28112-1 and second sidepanel 28112-2 (e.g., on the ends of the first and second side panelsopposite the releasably connected adapter plate 28014-1 or 28014-2).That is the tabs 28120 releasably interlock with the tab receivingopenings 28121.

The adapter plate (now removed from its temporary attachment to coverpanel 28110 as shown in FIG. 28A) can be releasably connected to formthe fourth side panel (e.g., the front) of the housing 28010. That isthe tabs 28120 on the front of the base panel 28108 and on the frontedges of the now vertically oriented first side panel 28112-1 and secondside panel 28112-2 can be mated with the corresponding tab receivingopenings 28121 of the adapter plate (28014-1 as shown in FIG. 28C or28014-2 as shown in FIG. 28D). In this example, to complete theconversion of the housing 28010 from the unfolded configuration to thefolded configuration, the cover panel 28110 can be folded over to formthe top of the housing 28010 as the tab receiving openings 28121 in thecover panel 28110 are mated with the corresponding tabs 28120 on the topedge of the adapter plate 28014-1 or 28014-2.

In one or more embodiments, and as illustrated in FIGS. 28A and 28B, thehousing 28010 can include a number of vertical surfaces (e.g., verticalsidewalls 28144) attached around at least a portion of the perimeter ofthe base panel 28108. The vertical surfaces 28144 can include a numberof horizontal tabs 28142 that extend outwardly from vertical surfaces28144. The tabs 28142 can partially define a radial channel for helpingto contain coiled fiber within the integral splice tray 28105.

As illustrated in FIGS. 28C and 28D, the housing 28010 can include anumber of thru holes 28133 configured to receive a snap in cableretainer (not shown). The thru holes 28133 correspond with boss elements28119 shown in FIGS. 28A and 28B. For instance, a snap in cable retainercan include installation barbs which correspond with thru holes 28133.The barbs can be snapped in thru holes 28133 to install the cableretainer. The barbs are shrouded by the boss elements 28119, whichprevents the barbs from causing fiber entanglement within the housing28110). As such, the thru holes 28133 and corresponding bosses 28119 canbe used for effective installation of a cable retainer, which canfacilitate cable management on the top of the housing 28010.

The housing 28010 also includes a number of rectangular thru holes28135, which can be used for attaching further fiber management elementson top of the housing 28010. For example, Velcro straps can be loopedthrough the thru holes 28135 and used to temporarily attach fibermanagement components to the cover 28110 of housing 28010. Asillustrated in FIGS. 28C and 28D, the housing 28010 can include a plate28139 that can be attached to the cover 28110 and configured to receivea printed label, for example.

The housing 28010 can also be easily, and repeatedly, converted from thefolded configuration shown in FIGS. 28C and 28D to the unfoldedconfiguration as shown in FIG. 28A or to a partially unfoldedconfiguration as shown in FIG. 28B by unfolding the panels of thehousing and releasing the tabs from the corresponding tab receivingopenings. As such, embodiments such as that shown in FIGS. 28A-28D canof the present disclosure can provide various benefits. For instance,embodiments of the present disclosure can allow a service technician toquickly, and repeatedly, access one or more optical components withinthe interior of the housing 28010 (e.g., to perform service functionssuch as splicing, cleaning and maintenance, etc.) without the use oftools. For instance, as described above, providing areleasable/removable adapter plate (e.g., 28014-1 and 28014-2) can alloweasy access to both sides of the adapter plate, which can facilitatecleaning both the exterior and interior sides of the connectors (e.g.,28015). That is, the adapter plate 28014-1 or 28014-2 can be removedfrom the housing 28010 while a number of optical connectors 28015coupled to the adapter plate 28014-1 and 28014-2 remain attached to acorresponding number of optical fibers (e.g., a number of fibers withinsplice tray 28105), in this manner, the optical fibers can be easilyremoved from the connectors for cleaning and maintenance.

FIG. 28E illustrates a rear view of the optical fiber management housingembodiments illustrated in FIGS. 28C and 28D. In one or moreembodiments, the housing 28010 can include a number of rear ports 28117.In the example illustrated in FIG. 28E, the housing 28010 includes oneSC port and one MPO/MPT port, as will be understood by those of ordinaryskill in the art. Embodiments are not limited to a particular number, ortype, of ports 28117. FIG. 28E also illustrates that one or more portplugs 28137 can be used to plug ports 28117 that are unused.

Embodiments of the present disclosure can also provide economic benefitssuch as reducing the costs associated with manufacturing, shipping, andstoring optical fiber management housings. For instance, as illustratedin FIG. 28A, in various embodiments, the components of the housing 28010can be simultaneously manufactured as a single piece (e.g., via aninjection molding process). Since the components of the embodimentillustrated in FIG. 28A are substantially within the same plane (e.g., aflat design) the housing 28010 can be shipped and stored in a flat(e.g., unfolded) configuration, which can reduce the amount of storagespace as compared to storing in the folded (e.g., assembled)configuration such as that shown in FIGS. 28C and 28D.

CONCLUSION

The present disclosure includes apparatus and methods for a modularoptical fiber cassette. One embodiment includes a base housingconfigured to receive additional nested components and an adapter plateresiliently connected to the housing and comprising a plurality ofoptical fiber connectors. The adapter plate is releasable from thehousing and providing access to both sides of the adapter plate. Thecassette further includes a radius limiter nested with and resilientlyconnected to the base housing, a first expansion housing having anexterior contour substantially aligned with the base housing andconfigured to resiliently interlock with the base housing, and a coverresiliently connected to the expansion housing.

Although specific embodiments have been illustrated and describedherein, those of ordinary skill in the art will appreciate that anarrangement calculated to achieve the same results can be substitutedfor the specific embodiments shown. This disclosure is intended to coveradaptations or variations of one or more embodiments of the presentdisclosure. It is to be understood that the above description has beenmade in an illustrative fashion, and not a restrictive one. Combinationof the above embodiments, and other embodiments not specificallydescribed herein will be apparent to those of skill in the art uponreviewing the above description. The scope of the one or moreembodiments of the present disclosure includes other applications inwhich the above structures and methods are used. Therefore, the scope ofone or more embodiments of the present disclosure should be determinedwith reference to the appended claims, along with the full range ofequivalents to which such claims are entitled.

In the foregoing Detailed Description, some features are groupedtogether in a single embodiment for the purpose of streamlining thedisclosure. This method of disclosure is not to be interpreted asreflecting an intention that the disclosed embodiments of the presentdisclosure have to use more features than are expressly recited in eachclaim. Rather, as the following claims reflect, inventive subject matterlies in less than all features of a single disclosed embodiment. Thus,the following claims are hereby incorporated into the DetailedDescription, with each claim standing on its own as a separateembodiment.

1. An optical fiber management housing comprising: a base panel havingan optical management component integrally formed thereon; a first sidepanel, a second side panel, and a third side panel each coupled to thebase panel via a respective living hinge; a cover panel coupled to oneof the first, second, and third side panels via a living hinge; whereinthe housing includes a folded configuration in which the panels arereleasably connected together and form the housing; and a removableadapter plate forming a fourth side panel of the housing when in thefolded configuration, the adapter plate configured for releasableconnection to the base panel, the cover panel, and two of the first,second, and third side panels; and wherein the housing includes anunfolded configuration providing access to the optical managementcomponent.
 2. The housing of claim 1, wherein the optical managementcomponent is a splice tray integrally formed on the base panel.
 3. Thehousing of claim 2, wherein the integral splice tray, the base panel,the first side panel, the second side panel, the third side panel, andthe cover panel are each made of a polypropylene material.
 4. Thehousing of claim 2, wherein the splice tray includes a plurality ofsplice channels.
 5. The housing of claim 2, further including a splicetray cover releasably connected to the splice tray.
 6. The housing ofclaim 1, wherein the removable adapter plate includes a number ofapertures therein configured to receive a corresponding number ofexternal optical connectors, the number of optical external opticalconnectors configured for attachment to a corresponding number ofinternal optical connectors coupled to a corresponding number of opticalfibers.
 7. The housing of claim 1, wherein the optical managementcomponent is an optical component mount integrally formed on the basepanel and configured for coupling to a particular optical component. 8.The housing of claim 7, wherein the particular optical componentincludes at least one of multiplexing and demultiplexing functionality.9. The housing of claim 1, wherein the base panel, the first side panel,the second side panel, and the third side panel each include at leastone of a tab and tab receiving opening for releasably coupling to acorresponding tab or tab receiving opening of at least one of the otherrespective panels.
 10. The housing of claim 1, wherein the removableadapter plate includes a first and a second mounting hole for providingcompatibility with an LGX standard.
 11. The housing of claim 1, whereinthe housing includes at least two different removable adapter platesthat can be interchanged to provide the fourth side panel of the housingwhen in the folded configuration.
 12. A method for using an opticalfiber management housing, the method comprising: accessing an opticalmanagement component on an interior of the housing by converting thehousing from a folded configuration to an unfolded configurationincluding: detaching a cover panel from a first side panel and a secondside panel of the housing, wherein the cover panel is coupled to a thirdside panel of the housing via a living hinge, and wherein the first sidepanel, the second side panel, and the third side panel are each coupledto a base panel of the housing via respective living hinges; removing anadapter plate from the housing; performing an optical managementoperation on the optical management component; and returning the housingfrom the unfolded configuration to the folded configuration.
 13. Themethod of claim 12, wherein accessing the optical management componenton the interior of the housing includes accessing a splice trayintegrally formed on the base panel of the housing.
 14. The method ofclaim 12, wherein converting the housing from the folded configurationto the unfolded configuration further includes unfolding the first,second, and third side panels such that they are in a same plane as thebase panel.
 15. The method of claim 14, wherein converting the housingfrom the folded configuration to the unfolded configuration furtherincludes unfolding the cover panel such that it is in the same plane asthe base panel.
 16. The method of claim 15, wherein returning thehousing from the unfolded configuration to the folded configurationincludes returning the first, second, and third sidewalls from the sameplane as the base panel to a plane substantially perpendicular to theplane of the base panel.
 17. The method of claim 12, including removingthe adapter plate from the housing while a number of optical connectorscoupled to the adapter plate remain attached to a corresponding numberof optical fibers.
 18. The method of claim 12, wherein each of the firstside panel, the second side panel, the third side panel, and the coverpanel include at least one of a tab and a tab receiving opening used toreleasably interlock with a corresponding tab or tab receiving openingto maintain the housing in the folded configuration, and whereinconverting the housing from the folded configuration to the unfoldedconfiguration further includes releasing respective tabs fromcorresponding respective tab receiving openings.
 19. The method of claim12, including removing the adapter plate from the housing prior todetaching the cover panel from the first side panel and the second sidepanel of the housing.
 20. The method of claim 12, wherein returning thehousing from the unfolded configuration to the folded configurationincludes replacing the adapter plate with a different adapter plate. 21.An optical fiber management housing system comprising: a base panelhaving a splice tray integrally formed thereon; a first side panel, asecond side panel, and a third side panel each coupled to the base panelvia a respective living hinge; a cover panel coupled to one of thefirst, second, and third side panels via a living hinge; wherein thehousing includes a folded configuration in which the panels arereleasably connected together and form the housing; and at least twodifferent removable adapter plates each configured to form a fourth sidepanel of the housing when in the folded configuration and eachconfigured for releasable connection to the base panel, the cover panel,and two of the first, second, and third side panels; and wherein thehousing includes an unfolded configuration providing access to thesplice tray.